docs: def get_scaling_relation_tuple(msr_dict):
      '''
      For a dictionary of scaling relation values convert string list to
      object list and then to tuple
      '''
  
      # Convert MSR string name to openquake.hazardlib.scalerel object
      for iloc, value in enumerate(msr_dict['Value']):
          if not value in SCALE_REL_MAP.keys():
              raise ValueError('Scaling relation %s not supported!' % value)
          msr_dict['Value'][iloc] = SCALE_REL_MAP[value]()
      return weight_list_to_tuple(msr_dict,
                                  'Magnitude Scaling Relation')